Mega Man Zero 3 is the best game for the Game Boy Advance to date.
The gameplay is what you'd expect from a Mega Man game - You jump, you shoot, you slash, you dash and you wall kick. Plus, Cyber Elves are more useful than in the first two games in the series. And you can use power chips for your body, your head and your foot. Plus, as you defeat bosses correctly, you get their EX Skills for powerful attacks. After the intro stage, you get two weapons: One is the Recoil Rod and the other is the Shield Boomerang.
The graphics are very nice. The only con in the graphics is that they look like a picture just a bit. Other than that, very nice graphics.
The sound is good too. The Buster sounds like it should sound, and the Saber is nice. Sorry, that's all I have to say.
Even if you are not a fan of the MMZ series, you can still find loads of replay value. There's pretty good challenge to gamers in the globe. So yeah - Replay value to everybody.
Overall, Mega Man Zero 3 is better than any other Mega Man game for the GBA, and it is the best GBA game ever. Whether or not you should consider yourself a Mega Man fan, MMZ3 will not disappoint.